Improvement in tubular steam-boilers



UNITED SfrA'rEs PATENT OFFICE.

JAMEs HOWARD AND EDWARD rrENNEY RoUsrIELD, or BEDFORD,

ENGLAND.

IMPROVEMENT IN TUBULAR STEAM`BO|`LERS. Y

Specification forming part of Letters PatentNo. ll 3,298, dated April/1,187i.

To all whom fit may concern:

Be itl known that we, JAMES HOWARD and EDWARD TENNEY BoUsErELD, ofBedford, in the county of Bedford, in England, have invented a new anduseful Improvement in Tubular Steam-Boilers and we do hereby declarethat ,the following is a full, clear, and exact description thereof,which will enable others skilled in the art to make land use the same,reference being had to the accompanying drawing, forming part of thisspecication. The tubular steam-boilers for which We have alreadyobtained. Letters Patent have been Constructed of groups of tubesconsisting of horizontal main tubes and vertical tubes rising from them,the steam being collected from the upperend of each vertical tube by adischargepipe common to the whole of the vertical tubes in the group.

Boilers composed of groups of tubes thus arranged, although generallysuccessful, have been found under certain circumstances to possess somedisadvantages. Thus, for example, a considerable height or headway isrequired to allow of the removal of a section or group of tubes or ofa-'single tube from the group, and this in confined situations, as onshipboard, is objectionable, and cannot always be secured. l

The short connecting-tubes and the horizontal tubes over them alsorender the examination and removal of Va vertical tube somewhatdifficult.

By our present improvements these disadvantages are overcome, and otheradvantages, to be presently noticed, are also secured, thus renderingtheboiler specially suited to marine and locomotive purposes.

We construct our improved boilers of sections or groups of tubes soarranged that the main connecting-tube of each section will be in orapproach a vertical position, with smaller tubes projectingfrom one sideof it, say, at right angles thereto, and secured to it by any approvedmethod.

The tubes which stand out at right angles to the main tube we prefer toconnect by water and steam ways with each other at both ends.

In the accompanying drawing Vour improvements are shown as applied tothe construction of amarine boiler provided withtwo hre-places, setabreast of each other.

Figure lis front view of the boiler. Fig. 2 is avertical section takenin the line l 2 of Fig. l. Fig. 3 is a vertical transverse section takenin the line 3 40E Fig. 2 and Fig. trepresents a horizontal andtransverse section of elastic packing-rings or washers we propose to usein packing the joints.

Similar letters of reference indicate corresponding parts. By referenceto Fig. 2 it will be seen that the improvedboiler is canted toward thefront, and consequently the main tubes which constitute the back of theboiler, and would otherwise be vertical, Vhave their upper ends slightlyinclined forward. It follows, therefore, that the tubes which areconnected therewith and stand forward at right angles thereto, areslightly canted out of the` horizontal. This is done to facilitate thecirculation of Water and steam in the boiler.

For the sake of clearness we will, however, in speaking of these tubes,refer to them as the vertical and the horizontal tubes, respectively. t,a, a a is a series of vertical tubes, formed with iiattened sides, andflttin g close together, so as to form a closed back for the furnace. f

Connected with each of .these tubes is a group of horizontal tubes, b bb, which are set parallel to and one above the other. These tubes Ab maybe screwed directly into the tubes a but we prefer to adopt the screwedcoupling-collars c, claimed under our patent vof 25th May, 1869, No.90,450.

In forming those sections which are intended to constitute the sides ofthe border, we place 'the tubes b b close together, as shown at Fig.

3, and they thus form the side walls of the furnace. The front ends ofthe tubes b are closed with a screw-plug, d. These screwplugs are eachfitted with a short central tube, which tubes communicate with thevertical tubes e c, which extend the whole depth of their severalsections. The tubes c e are closed at bottom, and severally connect attheir upper ends with a transverse steam-pipe, t'.

This arrangement of the tubes and connections enables us, by simplydisconnecting the tubes b of either section from the supply-pipe K andthe vertical tube eto withdraw such the water-supply pipe k. 'Y W Togivefreadyaccess to the lowestnrowof Y tubes b, which connect with thewater-supply pipe, this pipe is fitted with caps kf, the removal ofwhich will allow of the cleaningout of the tubes that are in line withthe uncovered' openings.

In order to insure tight joints for these covers, and for butt joints atother parts of the boiler, we have devised a novel kind of packing-ring,which is shown in place at y in Fig. 2, and is drawn on an enlargedscale at Fig. 4. On this packing-rin g we shall apply for a separatepatent, and in that application particularly point out its merits.

To provide for the rapid circulation of the water, we t into eachhorizontal water-tube which is near or adjacent to the fire a modicationof the internal tubes described in our v former patent. These innertubes (shown at f) are open at both ends, the end near the screw-capbeing left free, or supported in a central position merely by struts orspurs q. The other end of these tubes projects to about the middle ofthe tube a, and it is cut off at a sharp angle. The object of thusprojecting the tubes f into the vertical tubes a, and of cut. ting offtheir ends at a sharp angle, is to provide increased facilities for thecirculation of the Water in the tubes.

When the heated gases of the furnace impinge on the outside of thewater-tubes the steam and heated water will pass along the horizontaltubes b and rise in the vertical tube a. The said projecting ends oftubes j' arrest the'up-flowing currents in a'to some extent,

causing them to ow into tubes b below tubes f,thereby favoring theescape of the water from the latter above the projection.

The horizontal tubes above the water-line to a shortV distance belowmthewater-level; .ont .e .e we insert within each of these vertical tubes aa smaller vertical tube to receive the ends of the tubes f, and thusform a division in the tubes a. By this means an upward and downwardcurrent will be established within the vertical tubes a, and anefficient circulation of the water will be thereby secured throughoutthe sections. f

Having thus described our invention, we claim as new and desire tosecure by Letters Patent- 1. The vertical tube a, combined with theseries of horizontal tubes b and their centrallyarrangedcirculating-tubes f, as and for the purpose described.

2. The arrangement of the circulating-tubes f upon spurs axially withinthehorizontal tubes b, and projecting therefrom at one end, as and forthe purpose specified.

3. The construction of the circulating-tubes f, each wit-h projectingend cut obliquely, as and for the purpose specified.

In witness whereof we, the said JAMES HOWARD and EDWARD TENNEYBoUsFIELD, have hereunto set our hands the 5th day of December, in theyear of our Lord 1870.

JAMES HOWARD. EDWARD TENNEY BOUSFIELD.

Witnesses:

H. K. WHITE,

66 Chancery Lame. M. WYNN,

24 Royal Exchange.

